239 research outputs found

    Morphological characterisation of the coronary arteries in African sheep (Ovis orientalis). Differential analysis with those of humans and other animal species

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    Background: Despite the importance of the coronary system in the African sheep as a possible experimental model, there is little information about this particular vascular system. The objective of this investigation was to characterise morpho- logically the coronary arteries and their branches in African sheep.  Materials and methods: This descriptive cross-sectional study evaluated the coronary arteries and their branches of 62 hearts of short hair sheep. The right and left coronary ostia were perfused with a semi-synthetic resin (Palatal GP40L 85%; styrene 15%) dyed with mineral red. The morphological characteristics were evaluated using a digital calibrator and the biometrics of the coronary arteries and their branches were registered.  Results: The right coronary artery had a proximal calibre of 2.11 ± 0.46 mm. The subsinusal interventricular branch ended at the middle third of the homonym sulcus in 19 (30.6%) specimens. The left coronary artery had a diameter of 5.38 ± ± 1.59 mm and a length of 4.67 ± 3.32 mm. This artery bifurcated itself in the paraconal interventricular branch and the left circumflex branch in 57 (91.9%) hearts and trifurcated with an additional left diagonal branch in 5 (8.1%) spec- imens. Left coronary artery dominance was observed in 51 (82.3%) specimens, whereas in 11 (17.7%) cases the coronary circulation dominance was balanced.  Conclusions: Due to the similitude in the features of the coronary arteries between African sheep and humans, this animal model can be proposed for procedural and haemodynamic activities.

    Integrable potentials on spaces with curvature from quantum groups

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    A family of classical integrable systems defined on a deformation of the two-dimensional sphere, hyperbolic and (anti-)de Sitter spaces is constructed through Hamiltonians defined on the non-standard quantum deformation of a sl(2) Poisson coalgebra. All these spaces have a non-constant curvature that depends on the deformation parameter z. As particular cases, the analogues of the harmonic oscillator and Kepler--Coulomb potentials on such spaces are proposed. Another deformed Hamiltonian is also shown to provide superintegrable systems on the usual sphere, hyperbolic and (anti-)de Sitter spaces with a constant curvature that exactly coincides with z. According to each specific space, the resulting potential is interpreted as the superposition of a central harmonic oscillator with either two more oscillators or centrifugal barriers. The non-deformed limit z=0 of all these Hamiltonians can then be regarded as the zero-curvature limit (contraction) which leads to the corresponding (super)integrable systems on the flat Euclidean and Minkowskian spaces.Comment: 19 pages, 1 figure. Two references adde

    Gravity or turbulence? -III. Evidence of pure thermal Jeans fragmentation at ~0.1 pc scale

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    We combine previously published interferometric and single-dish data of relatively nearby massive dense cores that are actively forming stars to test whether their `fragmentation level' is controlled by turbulent or thermal support. We find no clear correlation between the fragmentation level and velocity dispersion, nor between the observed number of fragments and the number of fragments expected when the gravitationally unstable mass is calculated including various prescriptions for `turbulent support'. On the other hand, the best correlation is found for the case of pure thermal Jeans fragmentation, for which we infer a core formation efficiency around 13 per cent, consistent with previous works. We conclude that the dominant factor determining the fragmentation level of star-forming massive dense cores at 0.1 pc scale seems to be thermal Jeans fragmentation.Comment: accepted in MNRA

    Galilean quantum gravity with cosmological constant and the extended q-Heisenberg algebra

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    We define a theory of Galilean gravity in 2+1 dimensions with cosmological constant as a Chern-Simons gauge theory of the doubly-extended Newton-Hooke group, extending our previous study of classical and quantum gravity in 2+1 dimensions in the Galilean limit. We exhibit an r-matrix which is compatible with our Chern-Simons action (in a sense to be defined) and show that the associated bi-algebra structure of the Newton-Hooke Lie algebra is that of the classical double of the extended Heisenberg algebra. We deduce that, in the quantisation of the theory according to the combinatorial quantisation programme, much of the quantum theory is determined by the quantum double of the extended q-deformed Heisenberg algebra.Comment: 22 page

    Coupled dark matter-dark energy in light of near Universe observations

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    Cosmological analysis based on currently available observations are unable to rule out a sizeable coupling among the dark energy and dark matter fluids. We explore a variety of coupled dark matter-dark energy models, which satisfy cosmic microwave background constraints, in light of low redshift and near universe observations. We illustrate the phenomenology of different classes of dark coupling models, paying particular attention in distinguishing between effects that appear only on the expansion history and those that appear in the growth of structure. We find that while a broad class of dark coupling models are effectively models where general relativity (GR) is modified --and thus can be probed by a combination of tests for the expansion history and the growth of structure--, there is a class of dark coupling models where gravity is still GR, but the growth of perturbations is, in principle modified. While this effect is small in the specific models we have considered, one should bear in mind that an inconsistency between reconstructed expansion history and growth may not uniquely indicate deviations from GR. Our low redshift constraints arise from cosmic velocities, redshift space distortions and dark matter abundance in galaxy voids. We find that current data constrain the dimensionless coupling to be |xi|<0.2, but prospects from forthcoming data are for a significant improvement. Future, precise measurements of the Hubble constant, combined with high-precision constraints on the growth of structure, could provide the key to rule out dark coupling models which survive other tests. We shall exploit as well weak equivalence principle violation arguments, which have the potential to highly disfavour a broad family of coupled models.Comment: 34 pages, 6 figures; changes to match published versio

    Lynx: A knowledge-based AI service platform for content processing, enrichment and analysis for the legal domain

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    The EU-funded project Lynx focuses on the creation of a knowledge graph for the legal domain (Legal Knowledge Graph, LKG) and its use for the semantic processing, analysis and enrichment of documents from the legal domain. This article describes the use cases covered in the project, the entire developed platform and the semantic analysis services that operate on the documents. © 202

    Exposure to Bisphenol A and Phthalates during Pregnancy and Ultrasound Measures of Fetal Growth in the INMA-Sabadell Cohort

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    Background: Prenatal exposure to bisphenol A (BPA) and phthalates may affect fetal growth; however, previous findings are inconsistent and based on few studies. Objectives: We assessed whether prenatal exposure to BPA and phthalates was associated with fetal growth in a Spanish birth cohort of 488 mother–child pairs. Methods: We measured BPA and eight phthalates [four di(2-ethylhexyl) phthalate metabolites (DEHPm), mono-benzyl phthalate (MBzP), and three low-molecular-weight phthalate metabolites (LMWPm)] in two spot-urine samples collected during the first and third trimester of pregnancy. We estimated growth curves for femur length (FL), head circumference (HC), abdominal circumference (AC), biparietal diameter (BPD), and estimated fetal weight (EFW) during pregnancy (weeks 12–20 and 20–34), and for birth weight, birth length, head circumference at birth, and placental weight. Results: Overall, results did not support associations of exposure to BPA or DEHPm during pregnancy with fetal growth parameters. Prenatal MBzP exposure was positively associated with FL at 20–34 weeks, resulting in an increase of 3.70% of the average FL (95% CI: 0.75, 6.63%) per doubling of MBzP concentration. MBzP was positively associated with birth weight among boys (48 g; 95% CI: 6, 90) but not in girls (–27 g; 95% CI: –79, 25) (interaction p-value = 0.04). The LMWPm mono-n-butyl phthalate (MnBP) was negatively associated with HC at 12–20 pregnancy weeks [–4.88% of HC average (95% CI: –8.36, –1.36%)]. Conclusions: This study, one of the first to combine repeat exposure biomarker measurements and multiple growth measures during pregnancy, finds little evidence of associations of BPA or phthalate exposures with fetal growth. Phthalate metabolites MBzP and MnBP were associated with some fetal growth parameters, but these findings require replication

    Sublayer- and cell-type-specific neurodegenerative transcriptional trajectories in hippocampal sclerosis

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    Altres ajuts: Fundación Tatiana Pérez de Guzman el Bueno; SynCogDis Network (SAF2014-52624-REDT, SAF2017-90664-REDT); Human Frontiers Science Program (HFSP RGP0022/2013); Fondo Europeo de Desarrollo Regional (FEDER).Hippocampal sclerosis, the major neuropathological hallmark of temporal lobe epilepsy, is characterized by different patterns of neuronal loss. The mechanisms of cell-type-specific vulnerability and their progression and histopathological classification remain controversial. Using single-cell electrophysiology in vivo and immediate-early gene expression, we reveal that superficial CA1 pyramidal neurons are overactive in epileptic rodents. Bulk tissue and single-nucleus expression profiling disclose sublayer-specific transcriptomic signatures and robust microglial pro-inflammatory responses. Transcripts regulating neuronal processes such as voltage channels, synaptic signaling, and cell adhesion are deregulated differently by epilepsy across sublayers, whereas neurodegenerative signatures primarily involve superficial cells. Pseudotime analysis of gene expression in single nuclei and in situ validation reveal separated trajectories from health to epilepsy across cell types and identify a subset of superficial cells undergoing a later stage in neurodegeneration. Our findings indicate that sublayer- and cell-type-specific changes associated with selective CA1 neuronal damage contribute to progression of hippocampal sclerosis
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